St John's Tower is a compact but meaningful remnant of old Ayr, the surviving tower of the medieval church of St John the Baptist. Its importance lies less in scale than in history: the church is associated with the 16th-century parliament that confirmed Scotland's break with Rome during the Reformation.
The tower is an easy add-on while walking central Ayr, especially if you are already tracing the town's older layers beyond Burns connections and the seafront. It will not occupy you for long, but it gives Ayr a sharper historical anchor than many visitors expect from a resort town.